The invention relates to cycling mechanisms for firearms, specifically for semiautomatic mechanisms. Such mechanisms require that the cartridge be retained in the firing chamber essentially until the bullet has left the barrel or the projectile velocity and performance will be impaired. These cartridges, for example the 0.17 Winchester Super Magnum (WSM) and the 0.17 Hornady Magnum Rimfire (HMR) are relatively inexpensive compared to high power centerfire cartridges and therefore have high consumer appeal for the recreation sport shooting market. Traditional rimfire semiautomatic recycling mechanisms generally rely on the weight of the bolt for providing a delay in “blowback” of the bolt. These mechanisms have not been proven suitable for high power necked rimfire cartridges due to the higher power and much greater rearward blowback force associated with these cartridges. Such mechanisms, for these cartridges, do not provide enough delay in the blowback of the bolt or the bolt weight is excessively heavy. The cycling mechanisms for the more powerful necked centerfire cartridges are not suitable either in that the rimfire cartridges generally do not provide sufficient gas pressures for such mechanisms, for example, gas operated cycling mechanisms used in AR-15 type rifles. Even if such mechanisms could be adapted to the necked rimfire cartridges, such mechanism are complicated, requiring many moving parts and thus would be relatively expensive; particularly compared to semiautomatic .22 caliber non-necked rifles. Previous attempts at reasonably priced consumer oriented semiautomatic rifles for these high power rimfire cartridges have had performance issues, such as jamming and out-of-battery firing of cartridges. A reliable, mechanically simple, semiautomatic firearm with improved performance, particularly for high power necked rimfire cartridges, would be welcome.